Burglar alarm



Aug. 7, 1923. 1,414,650

A. man-MP BURGLAR ALARM Filed May 25 1922 Patented Aug. 7, 1923.

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ARCHIE J. SHIMP, O33 ROCKFORD, ILLINOIS.

BURGLAB ALARIVL Application filed May 25,

To all whom it may concern:

Be it known that I, AnoHIn J. SHIMP, a citizen of the United States,residing at Rockford, in the county of lVinnebago and State of Illinois,have invented certain new and useful Improvements in Burglar Alarms, ofwhich the following is a specification.

This invention pertains in general to burglar alarms, and has moreparticular reference to those of the portable type adapted to beattached to and actuated by a door knob, or to be actuated by a key or awindow cord for setting off the alarm.

The primary object of this invention is to provide a new and improvedburglar alarm of the character described. which comprises but few partsso compactly arranged as to make a small portable device which may beconveniently carried about, and which will serve in a practical andefficient manner the purposes intended.

I have also aimed to provide a burglar alarm which may be easily set andattached either to a door knob, a key, or in connection with a windowcord, and which will instantly sound an alarm upon actuation of any ofsaid parts.

Other objects and attendant advantages will be appreciated by thosefamiliar with this art as the invention becomes better understood byreference to the following description when considered in connectionwith the accompanying drawing, in which Figure 1 is a view of a portableburglar alarm embodying my invention attached to the shank of a doorknob in set position, with the bell removed;

Fig. 2 is a similar view showing the alarm set off;

Figs. 3 and 1 are sectional views taken on the lines 3-3 and 4-4,respectively, of Figs. 1 and 2;

Fig. 5 is a sectional view taken on the line,55 of Fig. 1;

Fig. 6 is a side view of the burglar alarm; and

Figs. 7 and 8 are face views of modified forms of the burglar alarm.

Referring more particularly to the drawings, Figs. 1 to 6 inclusive,show the preferred embodiment which is adapted for attachment to andactuation by a door knob. This comprises, generally stated, analarmsounding device, a setting device, and a trip plemental framemember 16.

1922. Serial No. 583,517.

device for setting 01f the alarm, which will be described in order.v

The alarm sounding device comprises a suitable hell 9 attached to acentral post 11, in turn fixed to a base of the frame member 12. Astriker, designated generally by 13, is adapted to be operated by asuitable spring motor for striking the inside of the bell for soundingthe alarm. In the present instance, this spring motor consists of aspiral spring 14 attached at its inner end to the post 11 and at itsouter end to one of the posts 15, which support a sup- This spring willbe wound by turning the bell 9, and the spring pressure will betransmitted through gearslr' to an escapement wheel 18. The escapementmember 19 co-operating with the wheel 18 is pivoted at 21 and fixed tothe striker 13. The striker has an arm 22 extending to the opposite sideof its pivot 21, which arm. is adapted to be nor mally held by thesetting device and to be released thereby for putting the striker intooperation.

The setting device comprises a spring member designated generally by 23,fixedly attached at its end 24 to the frame member 12 and having avertically disposed portion 25 the upper end 26 of which is adapted inthe set position of the member 28, to be disposed in the path of thestriker arm 22 as shown in Fig. 3, for preventing operation of thestriker. The spring member 23 is shown held in said set position by theupstanding part 26 of a setting member 27. This member 27 slidablymounted on the frame member 12 is adapted to be manually moved to theleft to the set position shown in Figs. 1 and 3 by pushing inwardly onthe projecting end 28. A contractile spring 29 connected at one end withthe frame 'member 12 and at its opposite end with ,shown in Fig. 1.

and upon movement of said member 27 to the dotted line position, thesoring member 23 will be slightly lowered until its depending finger 38rests on a trip member described later. This is the operative setposition in which the upper end 28 of the spring member still holds thestriker arm 22 against operation. The trip device comprises a tripmember 32 pivotally mounted at 33 on the frame member 12 and atrip-actuating member 3A pivotally mounted at 35 on a part 36 hinged at37 to the frame member. The inner end of the trip member- 32, disposedbeneath said depending finger 38, is notched at 39 and 4L1 for thereception of said finger 38, as will be presently described. Anysuitable connection may be provided between the mem: bers 32 and 3A foroscillating the former by the latter. The trip-actuating member 34 hasin the present instance a pair of spring. arms 42 adapted to bedetachably clamped to the shank of a door knob, as is plainly The outerend of the member 3e may, however, be suitably shaped for attachment toor connection with any part, movement of which is intended to set offthe alarm.

The operation of this form of my invention is as follows: The parts asshown in full lines in Figs. 1 and 3, are in the locked set position,that is, the setting member 27 has been pushed inwardly, thereby raisingthe spring member 23 to the settingposition and bearing against theadjacent edge of the trip member 32 so as to lock the same againsttripping movement. In this locked set position, the alarm device may beat-' tached to the door knob with little danger of accidentally settingoff the alarm. After the device has been properly attached, theattendant will pull the setting member 27 outwardly to the dotted lineposition shown in Fig. 3, thereby allowing the depending finger 38 torest on the inner end of thetrip member 32 in the operative setposition. When now the door knob is turned in either direction, thetrip-actuating member 34 will be oscillated, as for example in aclockwise direction, as shown in F 2, and will oscillate the trip member32 in the opposite 'di rection, thereby movin said trip member fromunder the finger 3S and allowing the latter to enter the notch 39 underthe. influence of the potential spring pressure of the member 23. Bythis movement of the spring member 23, its end will be withdrawn fromthe striker arm 22, thereby setting off the alarm. When it is desired toreset the device, it is only necessary to push in the setting member 27to the locked set position and pull said member out for the final settinposition. As shown in Fig. 6, the radially projecting trip-actuatingmember may be swung back on its hinged support against the back of theframe member 12, so that the alarm device occupies but very small spaceand may be conveniently carried in a pocketor any receptacle, such as agrip or suitcase.

In Fig. 7, I have shown a modified means for attaching my burglar alarmto-the alarm initiating or starting part which in this case is'the key43. In this form a supplemental part tel is provided which clamps to thespring arms a2 and has a key guide portion e6 which fits over the keyand serves to support the alarm device in the set position when the keyis in a horizontal position with the door locked. It will be manifestthat any attempt toturn the key from the opposite side of the doorbymeans of tools or instruments, or to dislodge the key will result insetting off the alarm.

in the modification shown in Fig. 3, l have provided a supplementalmember i8 adapted to be interposed between the window sash 49 and sashcord 51 and to be attached to the latter. This member has a pair ofoutstanding ears between which the spring arms 4-2 will be engaged. Itwill be manifest that when the window is moved, the member 48 will'betilted, thereby setting off the alarm.

It is believed that the foregoing conveys a clear understanding of theobjects prefaced above, and it should be understood that changes mightbe made in details of construction without departing from the spirit andscope of the invention as expressed in the appended claim.

I claim:

A burglar alarm comprising an alarm- {sorunding device including a ,belland a striker, a spring-actuating member adapted to be held in a setposition in which to prevent operation of said striker, a trip'memberfor holding said spring member in said set position and having recesseson opposed sides of said member, whereby upon movement ineithergdirection said spring member will enter one of said recesses andrelease the striker so that it will be free to sound the alarm.

ARCHIE J. SHIMP.

